Answer to the Parasite Case of the Week 662: Fasciola/Fasciolopsis/Echinostoma species eggs. The clinical history is most consistent with infection with the liver fluke, F. hepatica, rather than infection with an intestinal fluke. As mentioned by Bernardino, Florida Fan and SB, Fasciola gigantica is also in the differential diagnosis, based on the morphology of the eggs. However, it is not found in the Americas and can therefore be excluded.
Fasciola spp., Fasciolopsis buski, and Echinostoma eggs have a similar appearance, measuring up to 130-150 in greatest dimension, and having a small operculum. In particular, the eggs of Fasciola spp. and F. buski can be particularly challenging to differentiate, although the abopercular end of the former often has a roughened or irregular area. As noted by Sheldon, size matters in parasitology! The large size of these eggs allows similar appearing fluke and cestode eggs to be excluded from the differential.
Fasciola hepatica has an interesting life cycle. I would highly recommend checking out this really cool VIDEO on F. hepatica to see all of the different stages of the F. hepatica life cycle.
1 comment:
Dr. Pritt,
Thank you immensely for the impressive and informative video. The multitude of Parasitology students greatly learn from what you do and in turn they will use their learning to serve.
Your Fan in Florida
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